The present invention relates generally to induction systems for compressors and more particularly to such induction systems for refrigeration compressors which include noise attenuating means.
In design of high efficiency compressors it is important to provide relatively unrestricted suction gas flow to the compressor. However, this suction process results in the generation of substantial noise due both to the rapid flow of suction gas into the compressor as well as operation of the intake valving. Accordingly, it is desirable to provide some form of noise attenuating means in the suction gas flow path. However, it is also important to overall compressor efficiency to assure a relatively free unrestricted flow of suction gas to the compressor. Accordingly, the use of various forms of restrictors and baffles in the main flow path is undesirable in that such devices may create excessive flow losses requiring larger conduits be utilized to prevent compressor suction starvation.
As present practice requires the design of compressors to be as compact as possible, the available space within the assembly imposes several constraints on the size of suction mufflers. Further, because of these space limitations, it is often necessary to extend the suction gas conduit in close proximity to the discharge conduits. Accordingly, as the discharge gas is relatively hot due to the compression process, it is desirable to minimize heat transfer to the suction gas so as to maintain a high volumetric efficiency.
Accordingly, the present invention provides an induction system for a refrigeration compressor which includes a suction gas conduit assembly incorporating a suction muffler of the side branch resonator type which may be tuned to effectively attenuate any desired frequency noise generated by the suction process while still assuring a substantially unrestricted flow path for the suction gas. Preferably, the conduit assembly will be fabricated from a suitable plastic composition with the suction muffler integrally formed therewith in substantially axially parallel relationship so as to require only a minimal amount of space within the compressor. The use of a plastic composition not only enables fabrication of the conduit and associated sound attenuating means at relatively low cost but also minimizes the transfer of heat from the discharge gas to the suction gas thereby offering improved volumetric efficiency as well.
Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims taken in conjunction with the accompanying drawings.